A plasma display panel (or panel) is represented by an alternating-current surface discharge type panel, which is composed of a multiplicity of discharge cells formed between mutually opposite front board and rear board. The front board is composed of mutually parallel plural pairs of display electrode pairs each formed of a pair of scan electrode and sustain electrode formed on a front glass substrate, and a dielectric layer and a protective layer are formed to cover the display electrode pairs. The rear board is composed of a plurality of parallel data electrodes formed on a rear glass substrate, and a dielectric layer formed to cover them, and further a plurality of barrier walls are formed thereon parallel to the data electrodes, and a phosphor layer is formed on the surface of the dielectric layer and the side face of the barrier walls. The front board and the rear board are disposed oppositely and sealed so that the display electrode pairs and the data electrodes intersect three-dimensionally, and the inside discharge space is filled with a discharge gas containing xenon at partial pressure ratio of, for example, 5%. Discharge cells are formed in the opposing portions of the display electrode pairs and data electrodes. In the panel having such configuration, in each discharge cell, an ultraviolet ray is generated by gas discharge, and color phosphors of red (R), green (G), and blue (B) are excited by the ultraviolet ray to emit light, and a color display is formed.
The panel is driven generally by sub-field method, that is, one field period is divided into plural sub-fields, and light-emitting sub-fields are combined properly, and a gray scale display is made.
Each sub-field has an initializing period, an address period, and a sustain period. In the initializing period, an initializing discharge is generated, and a wall charge necessary for next address operation is formed on each electrode, and priming particles (explosives for discharging=exciting particles) are generated for generating the address discharge stably. In the address period, an address pulse voltage is selectively applied to the discharge cell for display, and an address discharge is generated to form a wall charge (this operation is called “address”). In the sustain period, a sustain pulse voltage is applied alternately to the display electrode pair formed of a scan electrode and a sustain electrode, and a sustain discharge is generated in the discharge cell causing the address discharge, and the phosphor layer of the corresponding discharge cell emit light, and an image is displayed.
In the sub-field method, a new driving method is developed, that is, the initializing discharge is generated by using a gently changing voltage waveform, and the discharge cell causing the sustain discharge is selectively initialized and discharged to minimize the light emission not relating to the gray scale display, and the contrast ratio is enhanced.
In this driving method, for example, in the initializing period of one sub-field out of the plurality of sub-fields, all discharge cells are initialized and discharged (that is, “all-cell initializing operation”), and in the initializing period of other sub-fields, only the discharge cells causing sustain discharge are initialized and discharged (that is, “selective initializing operation”). By driving in this manner, the light emission not relating to the image display is limited to the light emission by the all-cell initializing operation, and the luminance of black display region (“black luminance”) is only very weak light emission in the all-cell initializing operation, and an image display of high contrast is achieved (see, for example, patent document 1).
This patent document also discloses a so-called narrow width erase discharge, that is, the pulse width of the final sustain pulse in the sustain period is made shorter than the pulse width of other sustain pulses, and the potential difference by wall charge between the discharge electrode pairs is lessened. By generating this narrow width erase discharge stably, a reliable address operation is realized in the subsequent address period of sub-fields, and a plasma display device of high contrast ratio is realized.
Recently, in the trend of higher definition of panel and large area of screen, the plasma display device is demanded to be higher in the image display quality. One of the means for enhancing the image display quality is an elevation of luminance. To raise the luminance of light emission, it is effective to raise the partial pressure of xenon, but the voltage necessary for writing is increase, and the writing becomes unstable. In such panel, still more, the dark current (the current occurring in the discharge cells regardless of discharge) increases, and the wall charge formed in the initializing period decreases until the subsequent address operation (“discharge loss occurs”), and in spite of writing, sustain discharge does not occur in certain discharge cells (such cells are called “unlit cells”).    Patent document 1: Unexamined Japanese Patent Publication No. 2000-242224